Understanding of Linux GCC 4.4

Here I will share my understanding of Linux GCC 4.4 and discuss it with you. The Fedora Core Linux is developed in a community-supported way, and the development team of Red Hat Linux will continue to participate in the development of this release. Compared with lat_ops, par_ops is more like an advanced test. Through the modification and extension of the former, par_ops focuses on the parallel processing capability of the processor at the instruction level.

It uses DEMO code similar to that used in parallel computing in textbooks. As long as the processor supports parallel computing with the Linux GCC 4.4 compiler, it can be executed in parallel, the result reflects the degree of parallelism for different operations in each instruction cycle. This part of the test results are chaotic, except for some operations with the same degree of parallelism, it is difficult to find a linear variation pattern in other projects.

The vertical comparison is more likely to explain the problem. The o32 mode and the code compilation concurrency for the MIPS1 instruction set architecture are relatively low, code compiled for the R4600 processor in n32 mode has the highest degree of parallelism in many operations. The optimization capability of Linux GCC 4.4 For the dragon core 2F processor seems to be improved. Although the n64 mode has the highest degree of parallelism for the code compiled for the dragon core 2F, In the o32 and n32 modes, there is still a significant gap between the degree of parallelism for floating point variables and R4600.

In general, at the command level, the effect of optimizing and compiling the kernel 2F using Linux GCC 4.4 is quite obvious, which is particularly prominent in the 64-bit environment. We also used the-O2 and-O3 parameters to compile the code for optimizing the dragon core 2F and n32 modes respectively, to test the performance differences between the two. It may be that the code for testing the program is too simple. lat_ops and par_ops are not directly proportional to the increase in Compilation Time by further optimization.

Practical Application Testing

The next practical application performance test is more interesting. Based on the existing test conditions, Linux GCC 4.4 selects some common applications as test items and classifies them into two categories: desktop and network. The desktop includes three applications: virus detection, compression and packaging, and audio encoding. The time required to complete the task is considered; the Network Department builds a complete LAMPLinux/Apache/MySQL/PHP service in different system environments, test the maximum number of new transactions per second in different test cases using the Avalanche 2500 Application Layer performance tester of Cisco communications.

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